Re-evaluation of the endometriosis fertility index for predicting spontaneous pregnancy after surgery: a retrospective study

[Abstract] [Purpose]: To verify the efficacy of the endometriosis fertility index (EFI) for predicting spontaneous pregnancy after surgery for endometriosis. [Methods]: We retrospectively evaluated the predictive value of postoperative EFI for spontaneous pregnancy in 26 patients who underwent surgery for ovarian endometrioma in our institution between 2010 and 2016. [Results]: The median EFI score in all patients was 7, and the rate of spontaneous pregnancy after surgery was 35%. The cut-off EFI score obtained from the receiver operating characteristic (ROC) curve was 8 (AUC, 0.79; sensitivity, 0.67; specificity, 0.82). Rate of spontaneous pregnancy with EFI scores - 8 (18% vs. 67%, P = 0.028). Infertility treatment with assisted reproductive technology (ART) increased pregnancy rates in the lower EFI score group. [Conclusion]: We confirmed that the EFI was a reliable prediction tool for spontaneous pregnancy in patients with surgically treated endometriosis. In infertile patients with EFI scores